10 000 WATT FM BROADCAST TRANSMITTER
FM10
Page 5-29
01 October 2002
WARNING
(a) Perform a visual inspection on the power
supply fan assemblies (A27 and A28) or the
rear, lower panel for fan blockage. If a
blockage exists, it will be necessary to remove
the fan assembly or lower, rear panel and clean
the obstructed air path or replace the fan, as
required.
Dangerous voltages exist on terminals of power
transformer A1T1. Ensure the
MAIN POWER
circuit breaker is turned
OFF
before attempting to
remove a fan assembly or the rear, lower panel.
(b) Check fan fuses F6, F7 and F1 located on the
low voltage power supply PWB (A26A1). An
open circuit F6 or F7 will cause both fans in
the associated fan assembly to turn off. An
open circuit F1 will cause both fans on the rear,
lower panel to turn off.
5.11.15 RECTIFIER TEMPERATURE
ALARM: A rectifier temperature alarm can occur if
the temperature of one of the rectifier assemblies (A2
or A3) exceeds 90
°
C. Trouble shoot a rectifier
temperature alarm as follows:
Ensure that the assembly in question has had
sufficient time to cool off before proceeding.
(a) Perform a visual inspection on the power
supply fan assemblies (A27 and A28) and the
rectifier assemblies (A2 and A3) for fan
blockage.
(b) Check fan fuses A1F6 and A1F7 located on the
low voltage power supply PWB. A failed fuse
will cause the two fans in a fan assembly to
turn off.
AIR FILTERS
5.12
Air filters should be inspected and cleaned
periodically using soap and warm water. If the air
filters become damaged, they should be replaced as
soon as possible.
NOTE
Two types of air cooling are available for use with
the FM10. In an open air system, the transmitter
will contain four air filters, located in the rear
(Nautel part number - HR51). In a closed air
system, the transmitter will contain one air filter,
located at the top (Nautel part number - HR39).
BACKUP BATTERY
5.13
The transmitter's control/monitor PWB
contains a battery backup circuit which provides a
memory of alarm occurrences during AC power
failure. The three batteries [Nautel Part Number -
BT23 (1.5 VDC)] are monitored by a LOW BAT lamp
on the control/monitor PWB. If the LOW BAT lamp
turns on during normal operation of the transmitter,
the batteries should be replaced as soon as possible.
Refer to the instructions given in section 4, paragraph
4.10.1 for Control/Monitor Backup Battery
Installation.
REPLACEMENT OF COAXIAL CABLES
5.14
Coaxial cables in the transmitter's RF
stage have been made using specific material and cut
to predetermined, and often frequency dependent
lengths. If it is required to replace one of these
coaxial cables, contact the factory.
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